Qi can realize the devices international wireless charging. You can directly charge for the devices without any cables. Charging time is Nokia Lumia 920: 2.5-3 hours Samsung cellphone is 2-6 hours IPHONE is 3-4 hours other Andriod cellphone depends on the actual situation.

Features: Especially designed for Samsung Galaxy Note 2. Ultra-thin design compact and light weight without increasing additional weight of the Note 2. Adding wireless charging feature by piggybacking it on the battery of Note 2 it works well with any Qi-enabled charger. Easy to use. The receiver can be attached to the the battery all the time and it would not interrupt the normal use of the Note 2. Specifications: Color: Black Input power: WPC 5W Output: 1000mA Charging current: DC5V/500mA (Max) Charging time: about 5 hrs Reaction temperature: -10 ~ 40'C Working heat up range: below 20'C(ambient temperature below 25'C) Working ambient humidity: below 80% Working life: Charge & discharge above 4000 times Size: Approx. 65 x 54 x 1mm Weight: 5g / 0.17oz